Device For Collectting Rainwater And Solar Energy Originating From Visible Radiation

ABSTRACT

Device for collecting rainwater and heat originating from solar radiation to both drain the rainwater and generate sanitary or heating hot water, capable of being fitted at the base of a roof or on the edge of a balcony, comprising an open channel  2  having longitudinal walls and side walls  7, 8 , characterized in that a translucent or transparent covering element  3  is fitted inside the open channel  2 , being maintained by the side walls  7, 8  and defining inside the open channel a watertight sealed chamber  2   b , in that a heat-exchanger device  12  inside which a heat-transfer fluid can circulate is fitted inside said sealed chamber  2   b , and in that the translucent covering element  3  defines, with at least a part of a longitudinal wall of the channel  2 , a flow section for the rainwater.

The subject of the present invention is a device for recoveringrainwater and solar energy originating from light radiation. Thiscollection device is intended for buildings and is able to be mounted atthe base of a roof or on the edge of a balcony.

The importance that needs to be given to energy control is known,particularly in buildings, for developing solar devices capable ofreducing the energy divide.

Solar energy can be recovered by using solar sensors generallypositioned on the roof of the buildings. Inside these sensors aheat-transfer fluid is set in motion which can then be used to transmitthe heat inside the rooms, for example by means of individual solarwater heaters (ISWH) and/or floors fitted with passages for theheat-transfer fluid (sometimes called “direct solar floors” or COMBI).

Water- or heat-transfer fluid-based solar converters are known,generally made of metal or composite materials, comprising a bottom partconsisting of a box, an insulator, an absorber and a collector and a toppart consisting of a translucent or transparent panel thus providing agreenhouse effect. Also known are heat-transfer fluid-based solarconverters made of metallic materials and of glass that can be used invacuum operation.

Normally, these converter devices or solar sensors used in the buildingshave a flat geometry (assemblies of vacuum modules or tubes for an areaof 2 m×1 m for example) and have only a single functionality, to collectthe heat deriving from the solar radiation.

The object of the present invention is to increase the efficiency ofsolar energy collection compared to the devices normally used, thus toincrease the heat efficiency of these solar devices, and to propose asolar product that is fully integrated into the building, and having atleast a dual function of rainwater recovery and collection of the energyderiving from the solar radiation.

Another object of the present invention is to provide a device that islightweight, easy to fit and that can generate heat and/or electricity.

To this end, the present invention provides for the use of physicaleffects linked to the conversion of the solar radiation such asabsorption and the greenhouse effect by using for its structure acollection device mounted on the base of a roof of a building or on theedge of a building balcony.

Heat recovery is achieved through a heat exchanger using the greenhouseeffect, and which is installed on a sanitary or heating hot waterproduction device. The collection device thus offers a dual function,being capable of both recovering the rainwater and recovering the solarenergy to transmit it to a heat-transfer fluid which can be water oranother fluid. Furthermore, depending on the coating of theheat-exchanger's absorber, it is also possible to generate electricity.

In one embodiment, the device for collecting rainwater and energyoriginating from solar radiation that makes it possible to both drainthe rainwater and generate sanitary or heating hot water, or evenelectricity, can be mounted at the base of a roof or on the edge of abalcony and comprises an open channel having longitudinal walls and sidewalls.

A translucent or transparent covering element is fitted inside the openchannel, being maintained by the side walls and defining, inside theopen channel, a watertight sealed chamber.

A heat-exchanger device, inside which a heat-transfer fluid cancirculate, is fitted inside said sealed chamber.

The translucent covering element defines, with at least a part of alongitudinal wall of the channel, a flow section for the rainwater.

In one embodiment, the translucent or transparent covering elementcomprises a plate defining, with a part of the longitudinal walls, thewatertight sealed chamber.

Advantageously, the bottom part of the channel defines the watertightsealed chamber.

In another embodiment, the device also comprises at least onelongitudinal bottom wall positioned in the open channel at a distancefrom a bottom wall of the channel, said longitudinal bottom wall formingthe bottom of the watertight sealed chamber and partly delimiting theflow section for the rainwater.

The longitudinal bottom wall can be made of synthetic materials (polymeror composite type), glass, metal or alloy.

Advantageously, the longitudinal bottom wall extends from one of theinternal longitudinal walls of the open channel to the vicinity of theopposite internal longitudinal wall so as to leave a space between saidopposite internal wall and the longitudinal bottom wall.

In another embodiment, the translucent covering element is of generallytubular form.

Advantageously, the device comprises an additional trough positionedinside the open channel and partly surrounding the translucent coveringelement, said trough being covered by a reflecting element so as toincrease the solar concentration effect inside the translucent coveringelement. The additional trough is preferably connected to one of thelongitudinal walls of the open channel.

The absorber, which can have different inclinations according to thelatitude of the installation site and the geometry of the device,ensures an optimum solar radiation concentration effect with a highefficiency.

The open channel and the side walls can be made of synthetic materials(polymer or composite type), glass, metal or alloy.

The open channel, over its part concerning the recovery of solar heat,has a translucent or transparent covering providing the greenhouseeffect and can, in its bottom part, have an insulating plate.

The open channel, over its part concerning the evacuation of therainwater, can be coated on the inside, with a reflecting coating so asto increase the solar concentration effect.

In a preferred embodiment, the heat-exchanger device consists of a metalplate, preferably corrugated, which serves as an absorber, and at leastone metal pipe for carrying the heat-transfer fluid.

Preferably, the corrugated metal plate is coated on its top side with aselective black paint, a black coating produced by anodization, or amono- or polycrystalline silicon type mineral coating, absorbing theheat optimally and radiating in the long wavelengths, so maximizing thegreenhouse effect.

The metal pipe or pipes can be welded to the bottom side of thecorrugated metal plate and fixed to the side walls of the open channel.The corrugated profile provides for a greater heat efficiency byconcentration effect. There is advantageously a separation between thecorrugated metal plate and the translucent or transparent covering, sofavouring temperature rise inside the solar sensor part.

Advantageously, the metal plate is coated with at least one mineral toconvert the radiation into electricity. The mineral coating can, forexample, be silicon.

In another embodiment, the heat-exchanger device comprises at least onemetal or composite synthetic material line welded fixed to the sidewalls and used to convey the heat-transfer liquid.

Preferably, the metal line(s) is/are covered with a selective blackpaint, a black coating produced by anodization, or a mono- orpolycrystalline silicon type mineral coating, the lines made ofcomposite synthetic material incorporate black monochromatic polymers,so absorbing the heat optimally and radiating in the long wavelengths,so maximizing the greenhouse effect.

There is a separation between the metal or composite synthetic materiallines and the translucent or transparent covering, so favouringtemperature rise inside the solar sensor part.

In an advantageous embodiment, the side walls can be interlinked by asimple join, fitted together, glued or welded, which can be provided,for expansion effects, with a polymer seal.

The watertight sealed chamber can form a controlled-atmosphereenclosure.

The invention will be better understood from studying particularembodiments described as by no means limiting examples and illustratedby the appended drawings, in which:

FIG. 1 is a top view of a first embodiment of a device according to theinvention;

FIGS. 2, 3 and 4 are top views of individual modules intended to beassembled to form a second embodiment of a device according to theinvention;

FIG. 5 is a section through V-V of FIG. 1 showing the internal structureof the device;

FIG. 6 is a section through VI-VI of FIG. 1;

FIG. 7 is a section through VII-VII of FIG. 2, showing the internalstructure of the join of a module with another module or with arainwater down connector;

FIG. 8 is a cross-sectional view through VIII-VIII of FIG. 1;

FIG. 9 is a section corresponding to the section of FIG. 5 showing theinternal structure of a third embodiment of a device according to theinvention;

FIG. 10 is a section corresponding to the section of FIG. 6 showing theinternal structure of the third embodiment of a device according to theinvention;

FIG. 11 is a section showing the internal join structure of a module ofFIGS. 9 and 10 with another module of the same type or with a rainwaterdown connector to form a fourth embodiment of the invention;

FIG. 12 is a section corresponding to the section of FIG. 5 showing theinternal structure of a fifth embodiment of the invention;

FIG. 13 is a section corresponding to the section of FIG. 5 showing theinternal structure of a sixth embodiment of the invention;

FIG. 14 is a top view of a seventh embodiment of a device according tothe invention;

FIGS. 15, 16 and 17 are top views of individual modules intended to beassembled to form an eighth embodiment of a device according to theinvention;

FIG. 18 is a section through XVIII-XVIII of FIG. 14 showing the internalstructure of the device;

FIG. 19 is a section through XIX-XIX of FIG. 14;

FIG. 20 is a section corresponding to the section of FIG. 18 showing theinternal structure of a ninth embodiment of a device according to theinvention;

FIG. 21 is a section corresponding to the section of FIG. 19 showing theinternal structure of the ninth embodiment of the device according tothe invention;

FIG. 22 is a section corresponding to the section of FIG. 18 showing theinternal structure of a tenth embodiment of a device according to theinvention;

FIG. 23 is a section similar to that of FIG. 18, illustrating a variant;

FIG. 24 is a section similar to that of FIG. 22, illustrating a variant;

FIG. 25 is a section corresponding to the section of FIG. 18 showing theinternal structure of an eleventh embodiment of a device according tothe invention; and

FIG. 26 is a section through XXIV-XXIV of FIG. 14.

A first embodiment of the device for collecting rainwater and energyoriginating from solar radiation is referenced 1 overall in FIGS. 1, 5,6 and 8. The device 1 comprises an open channel 2, and a translucent ortransparent covering element or plate 3 of generally rectangular form.The device 1 is here represented mounted on the edge of a roof 19 of abuilding, like a conventional gutter.

Of course, the positioning of the device 1 on the edge of a roof 19 isby no means exclusive, it would also be possible to consider mountingthe device on the edge of a balcony.

The open channel 2 comprises on its two smallest sides, a flat side wall7 of the same section as the section of the open channel 2, asillustrated in FIG. 8. The open channel 2 also comprises, on itsopposite side, a flat side wall 8 of section delimited by a part of thesection of the open channel 2 and by one of the fixing strips 4 of thecovering plate 3, as illustrated in FIG. 7. The open channel 2 cancomprise, in different sections, one or several transverse flat plates 9of section delimited by a part of the section of the open channel 2 andby the bottom edge of the covering 3, as illustrated in FIG. 6, andthis, in order to reinforce the mechanical strength of the device, andso ensure a good rigidity.

The translucent or transparent covering plate 3 is fixed on its edges 10to the internal part of the open channel 2 and to the side walls 7, 8.Fixing strips 4 secure the covering plate 3.

The side wall 8 and the plates 9 provide support for the heat exchangerwhile the translucent or transparent covering plate 3 is supported bythe side walls 7 and 8 and the plates 9.

FIG. 5 illustrates the internal structure of the device 1. The plate 3defines, with the bottom part of the channel 2, a watertight sealedchamber 2 b. The watertight chamber 2 b is therefore defined by thecovering element 3 and a part of the longitudinal walls of the openchannel 2.

An insulating plate 11 can be fixed inside the channel 2. The plate 11has the same profile as the open channel 2 and thus covers all thebottom of the chamber 2 b. A heat exchanger 12 is fitted in the chamber2 b and comprises a corrugated metal plate 12 a on the bottom side ofwhich are fixed, for example by welding, two metal pipes 5. As avariant, it would also be possible to consider providing a single metalpipe.

The two metal pipes 5 enable a heat-transfer fluid to flow according tothe arrows 14 from one of the sides of the wall 8 to the wall 7 with areturn to the wall 8, for example through a 180° return bend not shownin the figures.

The two pipes 5 of the heat exchanger 12 end in two nozzles 6 whichproject inside the channel 2 and can be connected respectively to a feedand extraction pipe, or even to a 180° return bend, not shown in thefigures. These feed and extraction pipes can be incorporated in arainwater downpipe. This option makes it possible to fully integrate thedevice 1 in the structure of the building. As a variant, just a singlepipe could be used with nozzles located on both sides of the device.

To increase the heat efficiency, a reflecting coating can be applied tothe part open to the air 2 a of the internal side of the open channel 2(FIG. 5).

The collection device 1 illustrated in FIG. 1 can be divided up over itslength to then present several collection modules joined to each other.Examples of such modules, referenced 1 a, 1 b and 1 c, are illustratedin FIGS. 2, 3 and 4, in which similar elements are given the samereferences. It is thus possible to produce long collecting lengths.

The part of the open channel 2 intended to convey rainwater according tothe arrows 15, is here delimited by the part open to the air 2 a of theinternal side of the open channel 2 (FIG. 5) and by the translucent ortransparent covering plate 3. The rainwater is conveyed from the wall 7to the wall 8 and rainwater is collected over the entire length of thedevice referenced 1 or of the various modules referenced 1 a, 1 b and 1c.

A drip device 16 can be glued, welded or moulded on the bottom part ofthe open channel 2 (FIG. 5). A ventilation and evacuation orifice (notshown) can be provided through the side walls 7 and 8.

The material forming the channel 2 can be metal like that forming theheat exchanger 12. As a variant, the material forming the channel 2 canbe a synthetic polymer or any other material appropriate for collectingrainwater. It would also be possible to consider providing a vacuum inthe chamber 2 b.

Although the description has been given in relation to an exemplaryembodiment where the heat exchanger comprises two flow and returnpassages for a heat-transfer fluid, it would also be possible toenvisage a variant with just one heat-transfer fluid passage. It wouldalso be possible to consider an absorber comprising a flat metal plate.The geometry of the profile of the open channel 2 is in no way essentialand forms other than those illustrated could perfectly well be used.

The third embodiment of the water collection device illustrated in FIGS.9 and 10 differs from the embodiments of the preceding figures in thatthe open channel 2 also comprises a longitudinal bottom wall 17 fixed tothe side walls 7, 18 of the open channel 2, and a wall 21 extending saidbottom wall 17 upward towards the transparent covering plate 3. Saidcovering plate 3 is fixed on its edges 10 to the walls 7, 18, 21 and tothe internal longitudinal wall of the channel 2 located alongside theroof 19 of the building, with the fixing strips 4 securing the coveringplate 3.

The bottom wall 17 extends from the internal longitudinal wall of thechannel 2 located alongside the roof 19 of the building to the vicinityof the opposite internal longitudinal wall. The longitudinal bottom wall17 is positioned in the open channel 2, distanced from the bottom wallof the channel. For example, the wall 17 can be fitted at mid-height ofthe channel 2. Said longitudinal bottom wall forms the bottom of thewatertight sealed chamber 2 b, the wall 21 forming one of the sides ofsaid chamber. Thus, the chamber is delimited by the walls 7, 18, 17 and21, by the internal longitudinal wall of the channel 2 located alongsidethe roof 19 of the building, and by the covering plate 3.

The insulating plate 11 here has the same profile as that of the sealedchamber 2 b and covers the walls 17 and 21 and a portion of thelongitudinal internal wall of the channel located alongside the roof 19of the building.

The longitudinal bottom wall 17 leaves a space between the bottom wallof the channel and said wall 17. In a similar way, the wall 21 leaves aspace between itself and the longitudinal internal wall of the channellocated on the side opposite to the roof 19 of the building.

In other words, the watertight chamber 2 b is located in a top part ofthe channel 2, offset from the bottom and from the longitudinal internalwall of the channel located on the side opposite to the roof 19. Thus,the rainwater is conveyed on the translucent covering plate 3, but alsobetween the wall 21 and the part open to the air 2 a of the internalwall of the open channel, and between the wall 17 and the bottom wall ofthe channel.

In this embodiment, the rainwater can thus flow over the translucentcovering plate 3, over the side and under the chamber 2 b. The flowsection for the rainwater is therefore significantly increased.

As illustrated in FIG. 10, in order to reinforce the mechanicalresistance of the device and ensure a good rigidity, the open channel 2comprises, in different sections, one or more transverse flat plates 20delimited by the opposite longitudinal internal walls of the openchannel 2. The covering 3 and the longitudinal bottom wall 17 bear onone of the front sides of said transverse plates 20.

So as to obtain long collecting lengths, the device illustrated in FIGS.9 and 10 can be divided up over its length to present a number ofcollection modules joined to each other.

The internal structure of a join of one module to another module isrepresented in FIG. 11, which illustrates in section a flat side wall 18of the device delimited by one of the fixing strips 4 of the coveringplate 3, by the opposite longitudinal internal walls of the open channel2. The bottom wall 17 bears on the front side of the plate 18.

The multiple-collection device according to the invention presentsnumerous advantages regarding its integration in the buildings, itsbulk, its positioning, its weight since it can be modular and itsenhanced performance by concentration effect. As a variant, it wouldalso be possible to consider integrating the device in an existinggutter preferably having an identical profile and/or providing for avacuum to be created in the chamber 2 b.

As a variant, it would also be possible to consider providing adifferent arrangement illustrated in FIG. 12, in which the similarelements are given the same references, wherein the bottom wall 17extends from the internal longitudinal wall of the channel 2 located onthe side opposite to the roof 19 of the building. The wall 21 leaves aspace between itself and the longitudinal internal wall 22 of thechannel located alongside the roof 19 of the building. In this variant,the chamber 2 b is delimited by the walls 7, 18, 17 and 21, by theinternal longitudinal wall of the channel 2 located on the side oppositeto the roof 19 of the building, and by the covering plate 3.

In a variant of embodiment illustrated in FIG. 13 in which the identicalelements are given the same references, the chamber 2 b extends insidethe open channel 2, leaving a space on either side between itself andthe internal longitudinal walls of the channel, 2.

The chamber 2 b here comprises a wall 23 extending the bottom wall 17upward, on the side opposite to the wall 21, towards the transparentcovering plate 3. Thus, the wall 23 leaves a space between itself andthe longitudinal internal wall 22 of the channel located alongside theroof 19 of the building.

In these conditions, the chamber 2 b is delimited by the walls 7, 18,17, 21 and 23, and by the covering plate 3.

In order to reinforce the mechanical resistance of the device and ensurea good rigidity, it is possible to secure at least one of the walls 21and 23 of the chamber 2 b with the corresponding wall of the channel 2,for example using spacers.

In the embodiment illustrated in FIGS. 14, 18 and 19 in which similarelements are given the same references, the device 1 comprises a tubularcovering element or pipe 24 which is fixed at each of its free ends tothe transverse flat walls 25 that are added at each end of the openchannel 2. The pipe 24 is translucent or transparent.

The walls 25 are identical to each other and present a section partlydelimited by the section of the open channel 2 but leaving a spacebetween the bottom wall 2 a of the open channel 2 and their respectivebottom edge in order to allow rainwater to flow in said channel.

In this embodiment, the internal side wall of the pipe 24 thus delimitsthe watertight sealed chamber 2 b, in this case cylindrical, insidewhich the heat exchanger 12 is fitted.

The variant of embodiment illustrated in FIGS. 20 and 21 differs fromthe preceding embodiment in that the open channel 2 also comprises anadditional trough 26 extending inside said channel.

The trough 26 is provided with a rectilinear part 26 a extending, from atop free end of the longitudinal wall 27 opposite to the roof 19,towards the bottom wall 2 a, and a concave part 26 b oriented upwardwhich prolongs the free end of the rectilinear part 26. The concave part26 b presents a semi-circular profile. The concave part 26 b isconfigured so as to partly surround the bottom portion of the pipe 24,being located in the vicinity of said pipe 24. Inside the trough 26, therainwater is thus partially drained.

Advantageously, the trough 26 is coated on its bottom part with areflective covering (not represented) so as to increase the solarconcentration effect inside the sealed chamber 2 b which is locatedabove the concave part 26 b of the trough 26. In practice, in theseconditions, the solar radiation directed towards the trough 26 isreflected to the chamber 2 b, which significantly increases the solarenergy recovered by the device.

In other words, the design of such an additional trough 26 orientedupward, partly surrounding the pipe 24, and covered with a reflectivematerial, makes it possible to increase the heat efficiency of thedevice 1.

In this variant of embodiment, the device 1 comprises transverse flatwalls 27 which are added to each end of the open channel 2. The walls 27are identical to each other and have a section delimited by the sectionof the open channel 2, but leaving a space between the bottom wall 2 aof the open channel 2 and their respective bottom edge in order to allowrainwater to flow inside the open channel 2 and inside the trough 26.

In other words, in section, the bottom edges of the plates 27 are offsetupward relative to the bottom end of the trough 26.

In a variant of embodiment, the pipe 24 can also be provided with acylindrical metal plate covering the internal side wall of said pipe andlinked to the corrugated metal plate 12 a, and an additional externalcylindrical side wall delimiting a sealed cylindrical chamber radiallysurrounding the internal side wall of the pipe 24 and the heat exchanger12, said duly created additional chamber advantageously containing avacuum. In other words, this vacuum chamber surrounds the sealed chamber2 b.

The embodiment illustrated in FIG. 22 differs from the precedingembodiment illustrated in FIGS. 20 and 21 in that the trough 26 isconnected to the channel 2 alongside the side wall 22 by a wall 29extending the roof 19 outward so that the concave part 26 of the trough26 partially bears against the side wall 22.

In the variant of embodiment illustrated in FIG. 23, a plurality oftubular covering elements 24 are placed side by side in the open channel2. Apart from this particular feature, this variant is similar to thatof FIG. 18.

In a variant of embodiment illustrated in FIG. 24, which is similar tothat illustrated in FIG. 22, a plurality of tubular covering elements 24are placed side by side in the open channel 2. Furthermore, the channel26 has a number of concave parts 26 b, each surrounding a tubularcovering element 24.

In the variant of embodiment illustrated in FIG. 25 in which similarelements are given the same references as in FIGS. 18 to 22, the trough26 extends inside the open channel 2, leaving on either side a spacebetween itself and the internal longitudinal walls of the channel 2. Thetrough 26 thus leaves a space between the concave part 26 b and thelongitudinal wall 22, and between the rectilinear part 26 a and theopposite wall 2 a.

In order to reinforce the mechanical resistance of the device and ensurea good rigidity, it is possible to secure at least one of the parts 26 aand 26 b with the corresponding wall facing the channel 2, for exampleusing spacers.

As illustrated in FIG. 26, in order to reinforce the mechanicalresistance of the device 1, the open channel 2 advantageously comprises,in different sections, one or more transverse flat plates 29 of sectiondelimited by the section of the open channel 2, but leaving a spacebetween the bottom wall 2 a of the open channel 2 and their respectivebottom edge in order to allow rainwater to flow inside the open channel2 and inside the trough 26. The plates 28 also comprise a housing 30 forthe pipe 24 to pass through.

With the invention, a device for collecting rainwater and heatoriginating from solar radiation is obtained, in which the watertightsealed chamber for collecting solar energy is fitted inside the openchannel. The chamber is either partly delimited by a translucentcovering plate or formed by a translucent pipe.

In other words, regardless of the embodiment of the invention, thedevice forms a combined compact assembly in which the collection ofenergy is performed in the channel provided for rainwater flow.

Furthermore, regardless of the embodiment, it may be particularlyadvantageous to provide an additional trough oriented upward, partlysurrounding the watertight chamber which is either partly defined by thetranslucent covering plate, or delimited by the translucent pipe, andwhich is covered with a reflective material for increasing the heatefficiency of the device.

Moreover, the positioning of a channel oriented upward which is openover all its length makes it possible to obtain a device which providesthis dual energy and rainwater collection function in a particularlysimple and cost-effective way, while at the same time limiting the riskof water flowing outside of said channel.

The multiple-collection device according to the invention can beassociated, like a conventional gutter, with downpipes via downconnectors and, like a conventional solar sensor, with a regulation loopand a storage vessel or tank for storing the duly generated hot water,and/or with equipment using electricity for its operation.

1. Device for collecting rainwater and heat originating from solarradiation to both drain the rainwater and generate sanitary or heatinghot water, capable of being mounted at the base of a roof or on the edgeof a balcony, comprising an open channel (2) having longitudinal wallsand side walls (7, 8), characterized in that a translucent ortransparent covering element (3; 24) is fitted inside the open channel(2), being maintained by the side walls (7, 8) and defining, inside theopen channel, a watertight sealed chamber (2 b), in that aheat-exchanger device (12), inside which a heat-transfer fluid cancirculate, is fitted inside said sealed chamber (2 b), and in that thetranslucent covering element (3) defines, with at least a part of alongitudinal wall of the channel. (2), a flow section for the rainwater.2. Device according to claim 1, in which the translucent or transparentcovering element (3) comprises a plate defining, with a part of thelongitudinal walls, the watertight sealed chamber (2 b).
 3. Deviceaccording to claim 1 or 2, in which the bottom part of the channel (2)defines the watertight sealed chamber (2 b).
 4. Device according toclaim 1 or 2, also comprising at least one longitudinal bottom wall (17)positioned in the open channel at a distance from a bottom wall of thechannel, said longitudinal bottom wall forming the bottom of thewatertight sealed chamber (2 b) and partly delimiting the flow sectionfor the rainwater.
 5. Device according to claim 4, in which thelongitudinal bottom wall (17) extends from one of the internallongitudinal walls of the open channel to the vicinity of the oppositeinternal longitudinal wall so as to leave a space between said oppositeinternal wall and the longitudinal bottom wall (17).
 6. Device accordingto claim 1, in which the translucent covering element (24) is ofgenerally tubular form.
 7. Device according to any one of the precedingclaims, comprising an additional trough (26, 26 b) positioned inside theopen channel (2) and partly surrounding the translucent coveringelement, said trough being covered by a reflecting element so as toincrease the solar concentration effect inside the translucent coveringelement.
 8. Device according to claim 7, in which the additional trough(26) is preferably connected to one of the longitudinal walls of theopen channel (2).
 9. Device according to claim 6, in which a pluralityof tubular covering elements (24) are placed side by side.
 10. Deviceaccording to claims 7 and 9 taken together, in which the additionaltrough has several concave parts (26 b) each surrounding a tubularcovering element (24).
 11. Device according to any one of the precedingclaims, divided up over its length and having several modules (1 a, 1 band 1 c) joined to one another.
 12. Device according to any one of thepreceding claims, in which an insulating plate (11) is positioned on atleast a part of the internal side of the longitudinal walls of thebottom part of the open channel (2) inside the watertight sealed chamber(2 b).
 13. Device according to any one of the preceding claims, in whicha reflecting coating is applied to the internal side of a part open tothe air (2 a) of the longitudinal wall of the open channel (2). 14.Device according to any one of the preceding claims, in which one orseveral transverse flat plates (9), on which the bottom side of thecovering element (3) bears, are fitted in the bottom part of the channel(2) to increase its rigidity.
 15. Device according to any one of thepreceding claims, in which the material forming the open channel (2) isdifferent from that of the heat-exchanger device (12).
 16. Deviceaccording to any one of the preceding claims, in which theheat-exchanger device (12) comprises a corrugated metal plate (12 a) onthe bottom side of which is welded at least one metal pipe (5), in whichthe heat-transfer fluid circulates.
 17. Device according to claim 16, inwhich the metal plate (12 a) is coated with at least one mineral toconvert the radiation into electricity.
 18. Device according to any oneof the preceding claims, in which the watertight sealed chamber (2 b)forms a controlled-atmosphere enclosure.